This invention relates generally to the ink-jet printing art for ejecting ink droplets onto a recording medium, such as paper, and more particularly, to an ink tank cartridge for use in an ink-jet type recording apparatus such as a printer.
In a conventional recording apparatus, ink is supplied to a recording head from an ink tank constructed as a cartridge. A benefit of using an ink cartridge serving as an ink tank is that ink does not smear due to the leakage of ink while refilling new ink or the like. However, undesired air bubbles can easily enter the ink tank during the filling process which cause problems such as ink supply failure. Controlling the flow of ink from the cartridge is also a concern.
A cartridge can be divided into multiple chambers, where a porous foam is positioned over an outlet port in one chamber and free ink is filled into the other chamber. The free ink migrates from its chamber into the foam chamber. The foam in turn, controls the flow of ink that enters into an ink outlet port. Thus there is a need for converting a single chamber cartridge into a dual chamber cartridge so that either a foam member can occupy an entire single chamber of a cartridge or two chambers can be established wherein a foam member occupies one chamber and free ink occupies the other chamber.
Accordingly, it is desirable to develop a new and improved ink cartridge which would meet the above stated needs and others and provide better and more advantageous overall result.
Generally speaking, in accordance with the invention, an ink tank cartridge for an ink-jet type recording apparatus being removably mounted on an ink supply needle of a recording body is provided.
More particularly, the invention relates to an ink tank cartridge for an ink-jet type recording apparatus which is removably mounted onto an ink supply needle of the recording apparatus. The ink tank cartridge includes a housing comprising a plurality of walls forming a cavity and a bottom wall. An ink supply port extends through bottom wall. A removable divider wall or spacer is inserted into the cavity to form first and second chambers on opposite sides thereof.
A porous member is inserted into one of the chambers and abuts the supply port. The other chamber is at least partially filled with ink. The spacer has an opening to allow the ink to pass from the ink chamber to the foam chamber. The spacer is inserted into the chamber so that the opening is adjacent the bottom wall of the housing. The spacer is substantially U-shaped including a wall section and a parallel pair of legs extending therefrom.
A groove is formed in the bottom wall to direct and transfer ink from the porous member to the ink outlet port. A filter is positioned over the ink supply port and the groove. A cover is sealed to the top surface of the housing, preferably ultrasonic ally welded thereto, and includes a fill hole. A seal member is inserted into the supply port and is held in place by a retaining member.
Alternately, the spacer comprises a first section, a second section, and a third section where the first and second sections are hingedly connected to the third section. The spacer is inserted into the cavity where the wall sections abut opposing side walls of the housing to divide the cavity into first and second chambers.
A method for converting a single chamber ink-jet cartridge into a two chamber cartridge comprises the following steps. The spacer is bent to form a generally U-shaped conformation. The spacer is inserted into the housing cavity with the wall of the spacer toward a first end of the housing and with the legs of the spacer extending toward a second end of the housing in close proximity to the side walls of the housing. Thereby dividing the housing into first and second chambers. A notch or recess in the spacer is positioned to face the bottom wall of the housing and form a passage or opening from the first chamber to the second chamber.
A filter is inserted into the bottom surface of the housing above the ink outlet opening. Preferably, the filter is fused to the bottom wall. Then an ink absorbing member is inserted into one of the first and second chambers. A sealing member is inserted into the ink outlet port of the housing to prevent air from entering the cartridge. The seal member is held in place by attaching a retaining member around the outlet opening.
A cover is secured to a top portion of the housing, for example, by ultrasonic ally welding or fusing the cover to the housing. A negative pressure is applied to the cartridge to substantially remove air in a cartridge prior to filling the cartridge with ink. The cartridge is pressure filled with degassed ink through a fill hole in the cover. A negative pressure is then, again, applied to the cartridge to degas the ink, removing any air retained during the filling process. The fill hole is then sealed with a sealing member to prevent leakage and evaporation of the ink. The sealing member is a polypropylene coated foil attached to the top surface of the cover. The sealing member may be attached by a method such as thermal bonding or using adhesive.
Alternately, the cover may include a vent passage in addition to the fill hole. The vent passage is sealed by a valve adapted to permit selective flow of fluid through the vent passage. After the cartridge has been evacuated, pressure filled, and evacuated again through the fill port, the fill port is sealed and a negative pressure is applied to the cartridge by way of the valve in the vent passage to generate a negative pressure with the cartridge. The valve thereafter acts to maintain the negative pressure in the cartridge.
Sill other aspects of the invention will become apparent to those skilled in the art upon reading and understanding the following detailed description.